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Grunwald Y, Yaaran A, Moshelion M. Illuminating plant water dynamics: the role of light in leaf hydraulic regulation. THE NEW PHYTOLOGIST 2024; 241:1404-1414. [PMID: 38155452 DOI: 10.1111/nph.19497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 11/25/2023] [Indexed: 12/30/2023]
Abstract
Light intensity and quality influence photosynthesis directly but also have an indirect effect by increasing stomatal apertures and enhancing gas exchange. Consequently, in areas such as the upper canopy, a high water demand for transpiration and temperature regulation is created. This paper explores how light intensity and the natural high Blue-Light (BL) : Red-Light (RL) ratio in these areas, is important for controlling leaf hydraulic conductance (Kleaf ) by BL signal transduction, increasing water permeability in cells surrounding the vascular tissue, in supporting the enormous water demands. Conversely, shaded inner-canopy areas receive less radiation, have lower water and cooling demands, and exhibit reduced Kleaf due to diminished intensity and BL induction. Intriguingly, shaded leaves display higher water-use efficiency (compared with upper-canopy) due to decreased transpiration and cooling requirements while the presence of RL supports photosynthesis.
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Affiliation(s)
- Yael Grunwald
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel
- The Plant & Environmental Sciences Department, Weizmann Institute of Science, Rehovot, 7632706, Israel
| | - Adi Yaaran
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Menachem Moshelion
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel
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2
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Gao C, Marker SJV, Gundlach C, Poulsen HF, Bohr T, Schulz A. Tracing the opposing assimilate and nutrient flows in live conifer needles. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:6677-6691. [PMID: 37668473 DOI: 10.1093/jxb/erad334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 08/28/2023] [Indexed: 09/06/2023]
Abstract
The vasculature along conifer needles is fundamentally different from that in angiosperm leaves as it contains a unique transfusion tissue inside the bundle sheath. In this study, we used specific tracers to identify the pathway of photoassimilates from mesophyll to phloem, and the opposing pathway of nutrients from xylem to mesophyll. For symplasmic transport we applied esculin to the tip of attached pine needles and followed its movement down the phloem. For apoplasmic transport we let detached needles take up a membrane-impermeable contrast agent and used micro-X-ray computed tomography to map critical water exchange interfaces and domain borders. Microscopy and segmentation of the X-ray data enabled us to render and quantify the functional 3D structure of the water-filled apoplasm and the complementary symplasmic domain. The transfusion tracheid system formed a sponge-like apoplasmic domain that was blocked at the bundle sheath. Transfusion parenchyma cell chains bridged this domain as tortuous symplasmic pathways with strong local anisotropy which, as evidenced by the accumulation of esculin, pointed to the phloem flanks as the preferred phloem-loading path. Simple estimates supported a pivotal role of the bundle sheath, showing that a bidirectional movement of nutrient ions and assimilates is feasible and emphasizing the role of the bundle sheath in nutrient and assimilate exchange.
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Affiliation(s)
- Chen Gao
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Sean J V Marker
- Department of Physics, Technical University of Denmark. Fysikvej, 2800 Kgs. Lyngby, Denmark
| | - Carsten Gundlach
- Department of Physics, Technical University of Denmark. Fysikvej, 2800 Kgs. Lyngby, Denmark
| | - Henning F Poulsen
- Department of Physics, Technical University of Denmark. Fysikvej, 2800 Kgs. Lyngby, Denmark
| | - Tomas Bohr
- Department of Physics, Technical University of Denmark. Fysikvej, 2800 Kgs. Lyngby, Denmark
| | - Alexander Schulz
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
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3
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Paauw M, van Hulten M, Chatterjee S, Berg JA, Taks NW, Giesbers M, Richard MMS, van den Burg HA. Hydathode immunity protects the Arabidopsis leaf vasculature against colonization by bacterial pathogens. Curr Biol 2023; 33:697-710.e6. [PMID: 36731466 DOI: 10.1016/j.cub.2023.01.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 10/27/2022] [Accepted: 01/09/2023] [Indexed: 02/04/2023]
Abstract
Plants prevent disease by passively and actively protecting potential entry routes against invading microbes. For example, the plant immune system actively guards roots, wounds, and stomata. How plants prevent vascular disease upon bacterial entry via guttation fluids excreted from specialized glands at the leaf margin remains largely unknown. These so-called hydathodes release xylem sap when root pressure is too high. By studying hydathode colonization by both hydathode-adapted (Xanthomonas campestris pv. campestris) and non-adapted pathogenic bacteria (Pseudomonas syringae pv. tomato) in immunocompromised Arabidopsis mutants, we show that the immune hubs BAK1 and EDS1-PAD4-ADR1 restrict bacterial multiplication in hydathodes. Both immune hubs effectively confine bacterial pathogens to hydathodes and lower the number of successful escape events of an hydathode-adapted pathogen toward the xylem. A second layer of defense, which is dependent on the plant hormones' pipecolic acid and to a lesser extent on salicylic acid, reduces the vascular spread of the pathogen. Thus, besides glands, hydathodes represent a potent first line of defense against leaf-invading microbes.
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Affiliation(s)
- Misha Paauw
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Marieke van Hulten
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Sayantani Chatterjee
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Jeroen A Berg
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Nanne W Taks
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Marcel Giesbers
- Wageningen Electron Microscopy Centre, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 4, 6708 PB Wageningen, The Netherlands
| | - Manon M S Richard
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Harrold A van den Burg
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
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Grunwald Y, Gosa SC, Torne-Srivastava T, Moran N, Moshelion M. Out of the blue: Phototropins of the leaf vascular bundle sheath mediate the regulation of leaf hydraulic conductance by blue light. THE PLANT CELL 2022; 34:2328-2342. [PMID: 35285491 PMCID: PMC9134085 DOI: 10.1093/plcell/koac089] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 03/10/2022] [Indexed: 06/14/2023]
Abstract
The Arabidopsis (Arabidopsis thaliana) leaf veins bundle-sheath cells (BSCs)-a selective barrier to water and solutes entering the mesophyll-increase the leaf radial hydraulic conductance (Kleaf) by acidifying the xylem sap by their plasma membrane H+-ATPase, AHA2. Based on this and on the BSCs' expression of phototropins PHOT1 and PHOT2, and the known blue light (BL)-induced Kleaf increase, we hypothesized that, resembling the guard cells, BL perception by the BSCs' phots activates its H+-ATPase, which, consequently, upregulates Kleaf. Indeed, under BL, the Kleaf of the knockout mutant lines phot1-5, phot2-1, phot1-5 phot2-1, and aha2-4 was lower than that of the wild-type (WT). BSC-only-directed complementation of phot1-5 or aha2-4 by PHOT1 or AHA2, respectively, restored the BL-induced Kleaf increase. BSC-specific silencing of PHOT1 or PHOT2 prevented such Kleaf increase. A xylem-fed kinase inhibitor (tyrphostin 9) replicated this also in WT plants. White light-ineffective in the phot1-5 mutant-acidified the xylem sap (relative to darkness) in WT and in the PHOT1-complemented phot1-5. These results, supported by BL increase of BSC protoplasts' water permeability and cytosolic pH and their hyperpolarization by BL, identify the BSCs as a second phot-controlled water conductance element in leaves, in series with stomatal conductance. Through both, BL regulates the leaf water balance.
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Affiliation(s)
| | | | - Tanmayee Torne-Srivastava
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Nava Moran
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
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Hua L, Stevenson SR, Reyna-Llorens I, Xiong H, Kopriva S, Hibberd JM. The bundle sheath of rice is conditioned to play an active role in water transport as well as sulfur assimilation and jasmonic acid synthesis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 107:268-286. [PMID: 33901336 DOI: 10.1111/tpj.15292] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/16/2021] [Accepted: 04/20/2021] [Indexed: 06/12/2023]
Abstract
Leaves comprise multiple cell types but our knowledge of the patterns of gene expression that underpin their functional specialization is fragmentary. Our understanding and ability to undertake the rational redesign of these cells is therefore limited. We aimed to identify genes associated with the incompletely understood bundle sheath of C3 plants, which represents a key target associated with engineering traits such as C4 photosynthesis into Oryza sativa (rice). To better understand the veins, bundle sheath and mesophyll cells of rice, we used laser capture microdissection followed by deep sequencing. Gene expression of the mesophyll is conditioned to allow coenzyme metabolism and redox homeostasis, as well as photosynthesis. In contrast, the bundle sheath is specialized in water transport, sulphur assimilation and jasmonic acid biosynthesis. Despite the small chloroplast compartment of bundle sheath cells, substantial photosynthesis gene expression was detected. These patterns of gene expression were not associated with the presence or absence of specific transcription factors in each cell type, but were instead associated with gradients in expression across the leaf. Comparative analysis with C3 Arabidopsis identified a small gene set preferentially expressed in the bundle sheath cells of both species. This gene set included genes encoding transcription factors from 14 orthogroups and proteins allowing water transport, sulphate assimilation and jasmonic acid synthesis. The most parsimonious explanation for our findings is that bundle sheath cells from the last common ancestor of rice and Arabidopsis were specialized in this manner, and as the species diverged these patterns of gene expression have been maintained.
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Affiliation(s)
- Lei Hua
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
| | - Sean R Stevenson
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
| | - Ivan Reyna-Llorens
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
| | - Haiyan Xiong
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
| | - Stanislav Kopriva
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Zülpicher Str. 47b, Cologne, 50674, Germany
| | - Julian M Hibberd
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
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6
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Grunwald Y, Wigoda N, Sade N, Yaaran A, Torne T, Gosa SC, Moran N, Moshelion M. Arabidopsis leaf hydraulic conductance is regulated by xylem sap pH, controlled, in turn, by a P-type H + -ATPase of vascular bundle sheath cells. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:301-313. [PMID: 33735498 DOI: 10.1111/tpj.15235] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 03/06/2021] [Accepted: 03/09/2021] [Indexed: 05/28/2023]
Abstract
The leaf vascular bundle sheath cells (BSCs) that tightly envelop the leaf veins, are a selective and dynamic barrier to xylem sap water and solutes radially entering the mesophyll cells. Under normal conditions, xylem sap pH below 6 is presumably important for driving and regulating the transmembranal solute transport. Having discovered recently a differentially high expression of a BSC proton pump, AHA2, we now test the hypothesis that it regulates the xylem sap pH and leaf radial water fluxes. We monitored the xylem sap pH in the veins of detached leaves of wild-type Arabidopsis, AHA mutants and aha2 mutants complemented with AHA2 gene solely in BSCs. We tested an AHA inhibitor (vanadate) and stimulator (fusicoccin), and different pH buffers. We monitored their impact on the xylem sap pH and the leaf hydraulic conductance (Kleaf ), and the effect of pH on the water osmotic permeability (Pf ) of isolated BSCs protoplasts. We found that AHA2 is necessary for xylem sap acidification, and in turn, for elevating Kleaf . Conversely, AHA2 knockdown, which alkalinized the xylem sap, or, buffering its pH to 7.5, reduced Kleaf , and elevating external pH to 7.5 decreased the BSCs Pf . All these showed a causative link between AHA2 activity in BSCs and leaf radial hydraulic water conductance.
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Affiliation(s)
- Yael Grunwald
- The R.H. Smith Institute of Plant Sciences and Genetics in Agriculture, The R.H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Noa Wigoda
- The R.H. Smith Institute of Plant Sciences and Genetics in Agriculture, The R.H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Nir Sade
- The R.H. Smith Institute of Plant Sciences and Genetics in Agriculture, The R.H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences at Tel-Aviv University, Tel Aviv, 6997801, Israel
| | - Adi Yaaran
- The R.H. Smith Institute of Plant Sciences and Genetics in Agriculture, The R.H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Tanmayee Torne
- The R.H. Smith Institute of Plant Sciences and Genetics in Agriculture, The R.H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Sanbon Chaka Gosa
- The R.H. Smith Institute of Plant Sciences and Genetics in Agriculture, The R.H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Nava Moran
- The R.H. Smith Institute of Plant Sciences and Genetics in Agriculture, The R.H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Menachem Moshelion
- The R.H. Smith Institute of Plant Sciences and Genetics in Agriculture, The R.H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
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Verhage L. Pump it up! How xylem sap pH controls water transport in leaves. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:299-300. [PMID: 33913560 DOI: 10.1111/tpj.15265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
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8
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Yang T, Feng H, Zhang S, Xiao H, Hu Q, Chen G, Xuan W, Moran N, Murphy A, Yu L, Xu G. The Potassium Transporter OsHAK5 Alters Rice Architecture via ATP-Dependent Transmembrane Auxin Fluxes. PLANT COMMUNICATIONS 2020; 1:100052. [PMID: 33367257 PMCID: PMC7747981 DOI: 10.1016/j.xplc.2020.100052] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 05/29/2019] [Accepted: 04/27/2020] [Indexed: 05/24/2023]
Abstract
Plant HAK/KUP/KT family members function as plasma membrane (PM) H+/K+ symporters and may modulate chemiosmotically-driven polar auxin transport (PAT). Here, we show that inactivation of OsHAK5, a rice K+ transporter gene, decreased rootward and shootward PAT, tiller number, and the length of both lateral roots and root hairs, while OsHAK5 overexpression increased PAT, tiller number, and root hair length, irrespective of the K+ supply. Inhibitors of ATP-binding-cassette type-B transporters, NPA and BUM, abolished the OsHAK5-overexpression effect on PAT. The mechanistic basis of these changes included the OsHAK5-mediated decrease of transmembrane potential (depolarization), increase of extracellular pH, and increase of PM-ATPase activity. These findings highlight the dual roles of OsHAK5 in altering cellular chemiosmotic gradients (generated continuously by PM H+-ATPase) and regulating ATP-dependent auxin transport. Both functions may underlie the prominent effect of OsHAK5 on rice architecture, which may be exploited in the future to increase crop yield via genetic manipulations.
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Affiliation(s)
- Tianyuan Yang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Huimin Feng
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China
| | - Song Zhang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China
| | - Huojun Xiao
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China
| | - Qingdi Hu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China
| | - Guang Chen
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China
| | - Wei Xuan
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China
| | - Nava Moran
- The R.H. Smith Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Angus Murphy
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, USA
| | - Ling Yu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China
| | - Guohua Xu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China
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Attia Z, Dalal A, Moshelion M. Vascular bundle sheath and mesophyll cells modulate leaf water balance in response to chitin. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:1368-1377. [PMID: 31680316 DOI: 10.1111/tpj.14598] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 10/18/2019] [Accepted: 10/28/2019] [Indexed: 06/10/2023]
Abstract
Plants can detect pathogen invasion by sensing microbe-associated molecular patterns (MAMPs). This sensing process leads to the induction of defense responses. Numerous MAMP mechanisms of action have been described in and outside the guard cells. Here, we describe the effects of chitin, a MAMP found in fungal cell walls and insects, on the cellular osmotic water permeability (Pf ) of the leaf vascular bundle-sheath (BS) and mesophyll cells (MCs), and its subsequent effect on leaf hydraulic conductance (Kleaf ). BS is a parenchymatic tissue that tightly encases the vascular system. BS cells (BSCs) have been shown to influence Kleaf through changes in their Pf , for example, after sensing the abiotic stress response-regulating hormone abscisic acid. It was recently reported that, in Arabidopsis, the chitin receptors-like kinases, chitin elicitor receptor kinase 1 (CERK1) and LYSINE MOTIF RECEPTOR KINASE 5 (LYK5) are highly expressed in the BS as well as the neighboring mesophyll. Therefore, we studied the possible impact of chitin on these cells. Our results revealed that BSCs and MCs exhibit a sharp decrease in Pf in response to chitin treatment. In addition, xylem-fed chitin decreased Kleaf and led to stomatal closure. However, Atlyk5 mutant showed none of these responses. Complementing AtLYK5 in the BSCs (using the SCARECROW promoter) resulted in the response to chitin that was similar to that observed in the wild-type. These results suggest that BS play a role in the perception of apoplastic chitin and in initiating chitin-triggered immunity.
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Affiliation(s)
- Ziv Attia
- Faculty of Agriculture, Food and Environment, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Ahan Dalal
- Faculty of Agriculture, Food and Environment, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Menachem Moshelion
- Faculty of Agriculture, Food and Environment, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel
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10
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Aubry E, Dinant S, Vilaine F, Bellini C, Le Hir R. Lateral Transport of Organic and Inorganic Solutes. PLANTS (BASEL, SWITZERLAND) 2019; 8:E20. [PMID: 30650538 PMCID: PMC6358943 DOI: 10.3390/plants8010020] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/10/2019] [Accepted: 01/11/2019] [Indexed: 12/20/2022]
Abstract
Organic (e.g., sugars and amino acids) and inorganic (e.g., K⁺, Na⁺, PO₄2-, and SO₄2-) solutes are transported long-distance throughout plants. Lateral movement of these compounds between the xylem and the phloem, and vice versa, has also been reported in several plant species since the 1930s, and is believed to be important in the overall resource allocation. Studies of Arabidopsis thaliana have provided us with a better knowledge of the anatomical framework in which the lateral transport takes place, and have highlighted the role of specialized vascular and perivascular cells as an interface for solute exchanges. Important breakthroughs have also been made, mainly in Arabidopsis, in identifying some of the proteins involved in the cell-to-cell translocation of solutes, most notably a range of plasma membrane transporters that act in different cell types. Finally, in the future, state-of-art imaging techniques should help to better characterize the lateral transport of these compounds on a cellular level. This review brings the lateral transport of sugars and inorganic solutes back into focus and highlights its importance in terms of our overall understanding of plant resource allocation.
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Affiliation(s)
- Emilie Aubry
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France.
| | - Sylvie Dinant
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France.
| | - Françoise Vilaine
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France.
| | - Catherine Bellini
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France.
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, 90183 Umeå, Sweden.
| | - Rozenn Le Hir
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France.
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11
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Santa-María GE, Oliferuk S, Moriconi JI. KT-HAK-KUP transporters in major terrestrial photosynthetic organisms: A twenty years tale. JOURNAL OF PLANT PHYSIOLOGY 2018; 226:77-90. [PMID: 29704646 DOI: 10.1016/j.jplph.2018.04.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 04/04/2018] [Accepted: 04/15/2018] [Indexed: 05/24/2023]
Abstract
Since their discovery, twenty years ago, KT-HAK-KUP transporters have become a keystone to understand how alkali cation fluxes are controlled in major land-dwelling photosynthetic organisms. In this review we focus on their discovery, phylogeny, and functions, as well as the regulation of its canonical member, AtHAK5. We also address issues related to structure-function studies, and the technological possibilities opened up by recent findings. Available evidence suggests that this family of transporters underwent an early divergence into major groups following the conquest of land by embryophytes. KT-HAK-KUPs are necessary to accomplish several major developmental and growth processes, as well as to ensure plant responses to environmental injuries. Although the primary function of these transporters is to mediate potassium (K+) fluxes, some of them can also mediate sodium (Na+) and cesium (Cs+) transport, and contribute to maintenance of K+ (and Na+) homeostasis in different plant tissues. In addition, there is evidence for a role of some members of this family in auxin movement and in adenylate cyclase activity. Recent research, focusing on the regulation of the canonical member of this family, AtHAK5, revealed the existence of a complex network that involves transcriptional and post-transcriptional phenomena which control the enhancement of AtHAK5-mediated K+ uptake when Arabidopsis thaliana plants are faced with low K+ supply. In spite of the formidable advances made since their discovery, important subjects remain to be elucidated to gain a more complete knowledge of the roles and regulation of KT-HAK-KUPs, as well as to improve their use for innovative procedures in crop breeding.
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Affiliation(s)
- Guillermo E Santa-María
- Instituto Tecnológico Chascomús (INTECH), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Universidad Nacional de San Martín (UNSAM), Avda Intendente Marino km 8, 2. Chascomús, 7130, Provincia de Buenos Aires, Argentina.
| | - Sonia Oliferuk
- Instituto Tecnológico Chascomús (INTECH), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Universidad Nacional de San Martín (UNSAM), Avda Intendente Marino km 8, 2. Chascomús, 7130, Provincia de Buenos Aires, Argentina
| | - Jorge I Moriconi
- Instituto Tecnológico Chascomús (INTECH), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Universidad Nacional de San Martín (UNSAM), Avda Intendente Marino km 8, 2. Chascomús, 7130, Provincia de Buenos Aires, Argentina
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Lindberg S, Premkumar A, Rasmussen U, Schulz A, Lager I. Phospholipases AtPLDζ1 and AtPLDζ2 function differently in hypoxia. PHYSIOLOGIA PLANTARUM 2018; 162:98-108. [PMID: 28834646 DOI: 10.1111/ppl.12620] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 08/01/2017] [Accepted: 08/09/2017] [Indexed: 06/07/2023]
Abstract
Besides hydrolyzing different membrane phospholipids, plant phospholipases D and molecular species of their byproducts phosphatidic acids (PLDs/PAs) are involved in diverse cellular events such as membrane-cytoskeleton dynamics, hormone regulation and biotic and/or abiotic stress responses at cellular or subcellular levels. Among the 12 Arabidopsis PLD genes, PLDζ1 and PLDζ2 uniquely possess Ca2+ -independent phox (PX) and pleckstrin (PH) homology domains. Here, we report that mutants deficient in these PLDs, pldζ1 and pldζ2, show differential sensitivities to hypoxia stimulus. In the present study, we used protoplasts of wild type and mutants and compared the hypoxia-induced changes in the levels of three major signaling mediators such as cytoplasmic free calcium [Ca2+cyt. ], hydrogen peroxide (H2 O2 ) and PA. The concentrations of cytosolic Ca2+ and H2 O2 were determined by fluorescence microscopy and the fluorescent dyes Fura 2-AM and CM-H2 DCFDA, specific for calcium and H2 O2 , respectively, while PA production was analyzed by an enzymatic method. The study reveals that AtPLDζ1 is involved in reactive oxygen species (ROS) signaling, whereas AtPLDζ2 is involved in cytosolic Ca2+ signaling pathways during hypoxic stress. Hypoxia induces an elevation of PA level both in Wt and pldζ1, while the PA level is unchanged in pldζ2. Thus, it is likely that AtPLDζ2 is involved in PA production by a calcium signaling pathway, while AtPLDζ1 is more important in ROS signaling.
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Affiliation(s)
- Sylvia Lindberg
- Department of Ecology, Environmental and Plant Sciences, Stockholm University, Stockholm, SE-106 91, Sweden
| | - Albert Premkumar
- Department of Ecology, Environmental and Plant Sciences, Stockholm University, Stockholm, SE-106 91, Sweden
| | - Ulla Rasmussen
- Department of Ecology, Environmental and Plant Sciences, Stockholm University, Stockholm, SE-106 91, Sweden
| | - Alexander Schulz
- Center for Advanced Bioimaging, Department of Plant and Environmental Sciences, University of Copenhagen, Fredriksberg, DK-1871, Denmark
| | - Ida Lager
- Department of Plant Breeding, Swedish University of Agricultural Sciences, Alnarp, SE-230 53, Sweden
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Murphy A. Plant membranes and border control. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3037-3040. [PMID: 28899083 PMCID: PMC5853494 DOI: 10.1093/jxb/erx229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
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14
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Wigoda N, Pasmanik-Chor M, Yang T, Yu L, Moshelion M, Moran N. Differential gene expression and transport functionality in the bundle sheath versus mesophyll - a potential role in leaf mineral homeostasis. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3179-3190. [PMID: 28407076 PMCID: PMC5853479 DOI: 10.1093/jxb/erx067] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 02/09/2017] [Indexed: 05/08/2023]
Abstract
Under fluctuating ambient conditions, the ability of plants to maintain hydromineral homeostasis requires the tight control of long distance transport. This includes the control of radial transport within leaves, from veins to mesophyll. The bundle sheath is a structure that tightly wraps around leaf vasculature. It has been suggested to act as a selective barrier in the context of radial transport. This suggestion is based on recent physiological transport assays of bundle sheath cells (BSCs), as well as the anatomy of these cells.We hypothesized that the unique transport functionality of BSCs is apparent in their transcriptome. To test this, we compared the transcriptomes of individually hand-picked protoplasts of GFP-labeled BSCs and non-labeled mesophyll cells (MCs) from the leaves of Arabidopsis thaliana. Of the 90 genes differentially expressed between BSCs and MCs, 45% are membrane related and 20% transport related, a prominent example being the proton pump AHA2. Electrophysiological assays showed that the major AKT2-like membrane K+ conductances of BSCs and MCs had different voltage dependency ranges. Taken together, these differences may cause simultaneous but oppositely directed transmembrane K+ fluxes in BSCs and MCs, in otherwise similar conditions.
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Affiliation(s)
- Noa Wigoda
- The R.H. Smith Institute of Plant Sciences and Genetics in Agriculture, The R.H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | | | - Tianyuan Yang
- The R.H. Smith Institute of Plant Sciences and Genetics in Agriculture, The R.H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, P.R. China
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, P.R. China
| | - Ling Yu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, P.R. China
| | - Menachem Moshelion
- The R.H. Smith Institute of Plant Sciences and Genetics in Agriculture, The R.H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Nava Moran
- The R.H. Smith Institute of Plant Sciences and Genetics in Agriculture, The R.H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
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